A step towards a Type 1 Diabetes vaccine by using nanotherapy

Two years ago, the Immunology of Diabetes Research Group at the Germans Trias i Pujol Research Institute, member of the UAB-CIE Sphere, reported a new experimental immunotherapy that prevented the onset of Type 1 Diabetes in mice predisposed to the disease. This work led to more studies with the support of the Spanish Government, Catalan Government and private patrons with a keen interest in it. Thanks to this, a new step towards the creation of a vaccine has been made, which in the medium-term could be capable of preventing and even curing the disease in humans. The article published today in the scientific journal PLOS ONE describes this new step towards the creation of a vaccine.

Initially the researchers avoided the destruction of the insulin-producing pancreatic cells (beta cells) in the body by modifying the individual’s immune cells, known as dendritic cells. This important step requires the extraction of the subjects' dendritic cells for their subsequent manipulation and re-injection. The process is complex and costly. In a new study with mice researchers have achieved the same effect with a much simpler process. Nanoparticles called liposomes are created in the laboratory; when they are introduced into the body they arrest the destruction of the beta cells and avoid Diabetes development. This technique could be a much better candidate for a human vaccine. The invention is commercially protected and an international patent has been applied for.

Droplets of fat and water which can be produced on a large scale

Liposomes have been used in several medical treatments. They are not cells, but droplets with an external fat membrane, similar to cell membranes. They can be made using a very specialized process, but one that is easy and safe and also easy to scale up.

The key: beta cells in process of natural death

To complete this study Germans Trias researchers have worked together with a ICREA group from the Catalan Institute for Nanoscience and Nanotechnology (ICN2). The ICN2 is a Severo Ochoa Centre of Research Excellence located on Universitat Autònoma de Barcelona (UAB) Campus, and its mission is to seek nanotechnology solutions to challenges in the fields of biology, energy or technology. The diameter of the liposomes created for this collaborative work is from half to one micron. They were specifically generated to imitate beta cells of the pancreas that are in the process of programmed cell death (apoptosis). As the researchers showed during the previous studies, this is the way to prevent the body from destroying the beta cells and to allow it to recuperate immunological tolerance. The Catalan researchers are the first group in the world to use liposomes that imitate naturally dying cells to fight against Diabetes. The Universities of Barcelona and Lleida also contributed to this work.

Next steps 

After showing that liposomes prevent the onset of Type 1 Diabetes in mice, the next steps are to test it in human cells in vitro, to start clinical trials on human candidates for preventive vaccination and to cure the disease by combining the vaccine with regenerative therapies. The Germans Trias Institute plans to carry out these steps with patients at the hospital and to optimise the product by dosage and guideline studies. It is also planned to optimise the product for personalization. To achieve these objectives more competitive funding will be necessary from public agencies. The group is also studying collaborations and investment opportunities from the pharmaceutical industry. Private funding continues to be important and the Germans Trias Institute is studying the possibility of organizing a local campaign.

Growing incidence and complex consequences 
Type 1 Diabetes is an illness where the body does not recognize the beta cells of the pancreas as its own and destroys them. The organ produces less and less insulin, the hormone that allows us to process the sugar we eat. Patients must prick their fingers several times a day to check blood sugar levels and inject themselves with insulin in the stomach or other parts of the body. This constant control is not always easy and having too much or too little insulin can have severe consequences. The most serious is that in the long term hyperglycaemia provokes retinal damage that can lead to blindness, renal insufficiency, destruction of nerve fibres or what is called "Diabetics Foot" where ulcers form, leading eventually to the need to amputate.

The causes of the disease are unknown, although there are both genetic and environmental factors involved. About 0.3% of the population is affected and the incidence is increasing by 3-4% a year. It usually appears in children and young adults and it is incurable. This immunotherapy presents a possible solution for Type 1 Diabetes.

Source: http://www.nanotechnologyworld.org/#!A-step-towards-a-Type-1-Diabetes-vaccine-by-using-nanotherapy/c89r/5577096b0cf293eac807083b 

On-demand vaccines possible with engineered nanoparticles

This image shows a collection of vaccinating nanoparticles, which at
their largest are about 1,000 times smaller than a human hair. The
inset graphic is a representation of how the engineered proteins
decorate a nanoparticle’s surface.
Credit: University of Washington

Vaccines combat diseases and protect populations from outbreaks, but the life-saving technology leaves room for improvement. Vaccines usually are made en masse in centralized locations far removed from where they will be used. They are expensive to ship and keep refrigerated and they tend to have short shelf lives.

University of Washington engineers hope a new type of vaccine they have shown to work in mice will one day make it cheaper and easy to manufacture on-demand vaccines for humans. Immunizations could be administered within minutes where and when a disease is breaking out.

“We’re really excited about this technology because it makes it possible to produce a vaccine on the spot. For instance, a field doctor could see the beginnings of an epidemic, make vaccine doses right away, and blanket vaccinate the entire population in the affected area to prevent the spread of an epidemic,” said François Baneyx, a UW professor of chemical engineering and lead author of a recent paper published online in the journal Nanomedicine.

The research was funded by a Grand Challenges Explorations grant from the Bill & Melinda Gates Foundation and the National Institutes of Health.

In typical vaccines, weakened pathogens or proteins found on the surface of microbes and viruses are injected into the body along with compounds called adjuvants to prepare a person’s immune system to fight a particular disease. But standard formulations don’t always work, and the field is seeking ways to manufacture vaccines quicker, cheaper and tailored to specific infectious agents, Baneyx said.

The UW team injected mice with nanoparticles synthesized using an engineered protein that both mimics the effect of an infection and binds to calcium phosphate, the inorganic compound found in teeth and bones. After eight months, mice that contracted the disease made threefold the number of protective “killer” T-cells – a sign of a long-lasting immune response – compared with mice that had received the protein but no calcium phosphate nanoparticles.

The nanoparticles appear to work by ferrying the protein to the lymph nodes where they have a higher chance of meeting dendritic cells, a type of immune cell that is scarce in the skin and muscles, but plays a key role in activating strong immune responses.

In a real-life scenario, genetically engineered proteins based on those displayed at the surface of pathogens would be freeze-dried or dehydrated and mixed with water, calcium and phosphate to make the nanoparticles. This should work with many different diseases and be especially useful for viral infections that are hard to vaccinate against, Baneyx said.

He cautioned, however, that it has only been proven in mice, and the development of vaccines using this method hasn’t begun for humans.

The approach could be useful in the future for vaccinating people in developing countries, especially when lead time and resources are scarce, Baneyx said. It would cut costs by not having to rely on refrigeration, and vaccines could be produced with rudimentary equipment in more precise, targeted numbers. The vaccines could be manufactured and delivered using a disposable patch, like a bandage, which could one day lessen the use of trained personnel and hypodermic needles.

Co-authors of the paper are Weibin Zhou, Albanus Moguche and David Chiu of the UW, and Kaja Murali-Krishna of Emory University.

Source: http://www.washington.edu/news/2014/01/07/on-demand-vaccines-possible-with-engineered-nanoparticles/

UCSD scientists invent MRSA 'nanosponge' vaccine

The glowing yellow specks in the image show uptake
of the nanosponge vaccine by a mouse dendritic cell --
an immune-system cell. The MRSA toxins were labeled with
a fluorescent dye which glows yellow. The nanosponge vaccine
with detained toxins and can be seen glowing yellow
after uptake by the dendritic cell. The cell is membrane
stained red and the nuclei stained blue.
— UC San Diego Department of NanoEngineering

UCSD scientists have created a vaccine for the deadly MRSA infection, using 'nanosponge' technology they previously used to soak up MRSA toxins and other poisons and venoms. The vaccine is effective in mice, they showed in a study; and their goal is to get it into human clinical trials.

The nanosponges are built on a polymer core wrapped with membranes from red blood cells that seize the toxins. They were first loaded with the MRSA toxins and injected into mice. The mouse immune system recognized the toxins and developed antibodies. The vaccinated mice were then able to survive an otherwise lethal dose of the toxins.

The study was published Sunday in Nature Nanotechnology. Liangfang Zhang, a nanoengineering professor at UC San Diego Jacobs School of Engineering, was senior author on the paper.

MRSA, or methicillin-resistant Staphylococcus aureus, has become one of the "superbugs" plaguing hospitals, and even some locations outside hospitals, because it has evolved potent resistance to antibiotics. The prospect of antibiotics becoming useless has become a nightmare scenario for modern health care. Without effective antibiotics, infections that were once easily treatable could once again become fatal, as they often were in the days before antibiotics were discovered.

But MRSA's lethality is mainly indirect, through a toxin called alpha-haemolysin. The toxin kills cells by punching holes in them. If that toxin were to be neutralized, the bacterium would be much less dangerous.

"With our toxoid vaccine, we don't have to worry about antibiotic resistance. We directly target the alpha-haemolysin toxin," Zhang said in a UCSD news release.

The nanosponge vaccine solves a tricky problem in vaccinating against MRSA, Zhang said. The toxin from MRSA is too dangerous to be given unaltered. So it is heated or chemically treated to weaken it for vaccine development.. But the altered toxin is less effective in provoking an effective antibody response than the unaltered toxin.

Immune cells called dendritic cells seek out the toxin-laden vaccine and process it, leading to antibody production by other immune cells. Free toxin kills dendritic cells, but trapping it in the vaccine's membrane reduces its dangerous without altering the toxin itself.

"The researchers found that their nanosponge vaccine was safe and more effective than toxoid vaccines made from heat-treated staph toxin," the news release stated. "After one injection, just 10 percent of staph-infected mice treated with the heated version survived, compared to 50 percent for those who received the nanosponge vaccine. With two more booster shots, survival rates with the nanosponge vaccine were up to 100 percent, compared to 90 percent with the heat-treated toxin."

Previously, "there was no way you could deliver a native toxin to the immune cells without damaging the cells," Zhang said in the release. "But this technology allows us to do this."

In April, Zhang and colleagues published a paper in Nature Nanotechnology showing how the nanosponges could increase survival of mice injected with toxins from MRSA and other sources.

The nanosponges soaked up the toxins, which adhered to the red blood cell membranes. By reducing the amount of freely circulating toxins, the nanosponges increased survival.

Liangfang Zhang, a nanoengineer at UC San Diego, is coating drug-filled particles with the skin of red blood cells in hopes that something natural will disguise something fake from the immune system, which flushes out invaders. — Eduardo Contreras

Zhang and colleagues originally developed the nanosponges as a delivery vehicle for cancer drugs. The goal was to keep the drugs active in the body for longer periods of time, by guarding them against detection and destruction by the immune system.

Source: http://www.utsandiego.com/news/2013/dec/01/vaccine-nanoparticles-ucsd-efficient/

Nanoparticle vaccine offers better protection

Particles that deliver vaccines directly to mucosal surfaces could defend against many infectious diseases.

Many viruses and bacteria infect humans through mucosal surfaces, such as those in the lungs, gastrointestinal tract and reproductive tract. To help fight these pathogens, scientists are working on vaccines that can establish a front line of defense at mucosal surfaces.

Vaccines can be delivered to the lungs via an aerosol spray, but the lungs often clear away the vaccine before it can provoke an immune response. To overcome that, MIT engineers have developed a new type of nanoparticle that protects the vaccine long enough to generate a strong immune response — not only in the lungs, but also in mucosal surfaces far from the vaccination site, such as the gastrointestinal and reproductive tracts.

Such vaccines could help protect against influenza and other respiratory viruses, or prevent sexually transmitted diseases such as HIV, herpes simplex virus and human papilloma virus, says Darrell Irvine, an MIT professor of materials science and engineering and biological engineering and the leader of the research team. He is also exploring use of the particles to deliver cancer vaccines.

“This is a good example of a project where the same technology can be applied in cancer and in infectious disease. It’s a platform technology to deliver a vaccine of interest,” says Irvine, who is a member of MIT’s Koch Institute for Integrative Cancer Research and the Ragon Institute of Massachusetts General Hospital, MIT and Harvard University. 

Irvine and colleagues describe the nanoparticle vaccine in the Sept. 25 issue of Science Translational Medicine. Lead authors of the paper are recent PhD recipient Adrienne Li and former MIT postdoc James Moon.

Sturdier vaccines

Only a handful of mucosal vaccines have been approved for human use; the best-known example is the Sabin polio vaccine, which is given orally and absorbed in the digestive tract. There is also a flu vaccine delivered by nasal spray, and mucosal vaccines against cholera, rotavirus and typhoid fever.  

To create better ways of delivering such vaccines, Irvine and his colleagues built upon a nanoparticle they developed two years ago. The protein fragments that make up the vaccine are encased in a sphere made of several layers of lipids that are chemically “stapled” to one another, making the particles more durable inside the body. 

“It’s like going from a soap bubble to a rubber tire. You have something that’s chemically much more resistant to disassembly,” Irvine says.

This allows the particles to resist disintegration once they reach the lungs. With this sturdier packaging, the protein vaccine remains in the lungs long enough for immune cells lining the surface of the lungs to grab them and deliver them to T cells. Activating T cells is a critical step for the immune system to form a memory of the vaccine particles so it will be primed to respond again during an infection.

Stopping the spread of infection

In studies of mice, the researchers found that HIV or cancer antigens encapsulated in nanoparticles were taken up by immune cells much more successfully than vaccine delivered to the lungs or under the skin without being trapped in nanoparticles.  

HIV does not infect mice, so to test the immune response generated by the vaccines, the researchers infected the mice with a version of the vaccinia virus that was engineered to produce the HIV protein delivered by the vaccine. 

Mice vaccinated with nanoparticles were able to quickly contain the virus and prevent it from escaping the lungs. Vaccinia virus usually spreads to the ovaries soon after infection, but the researchers found that the vaccinia virus in the ovaries of mice vaccinated with nanoparticles was undetectable, while substantial viral concentrations were found in mice that received other forms of the vaccine. 

Mice that received the nanoparticle vaccine lost a small amount of weight after infection but then fully recovered, whereas the viral challenge was 100 percent lethal to mice who received the non-nanoparticle vaccine.

“Giving the vaccine at the mucosal surface in the nanocapsule form allowed us to completely block that systemic infection,” Irvine says. 

The researchers also found a strong memory T cell presence at distant mucosal surfaces, including in the digestive and reproductive tracts. “An important caveat is that although immunity at distant mucus membranes following vaccination at one mucosal surface has been seen in humans as well, it’s still being worked out whether the patterns seen in mice are fully reproduced in humans,” Irvine says. “It might be that it’s a different mucosal surface that gets stimulated from the lungs or from oral delivery in humans.”

Melissa Herbst-Kralovetz, an assistant professor of basic medical sciences at the University of Arizona College of Medicine, says the nanoparticles are “an exciting and effective strategy for inducing effector-memory T-cell responses to nonreplicating subunit vaccines through mucosal vaccination.”

“More research will need to be conducted to determine the delivery approach to be used in humans, but this vaccination strategy is particularly important for diseases that may require significant T cell-mediated protection, such as HIV,” says Herbst-Kralovetz, who was not part of the research team. 

Tumor defense

The particles also hold promise for delivering cancer vaccines, which stimulate the body’s own immune system to destroy tumors. 

To test this, the researchers first implanted the mice with melanoma tumors that were engineered to express ovalbumin, a protein found in egg whites. Three days later, they vaccinated the mice with ovalbumin. They found that mice given the nanoparticle form of the vaccine completely rejected the tumors, while mice given the uncoated vaccine did not.

Further studies need to be done with more challenging tumor models, Irvine says. In the future, tests with vaccines targeted to proteins expressed by cancer cells would be necessary. 

The research was funded by the National Cancer Institute, the Ragon Institute, the Bill and Melinda Gates Foundation, the U.S. Department of Defense and the National Institutes of Health.

The nanoparticle technology has been patented and licensed to a company called Vedantra, which is now developing infectious-disease and cancer vaccines.

Source: http://web.mit.edu/newsoffice/2013/nanoparticle-vaccine-offers-better-protection-0925.html